1. Field of the Invention
The present invention relates to a multilink-type robot capable of a plurality of articulatons.
2. Description of the Prior Art
Known multilink-type robots comprise an arm support swingable about a vertical axis, a first arm pivotably supported on the arm support, a second arm pivotably supported on the first arm, and a wrist unit pivotably supported on the second arm at a distal end thereof. It is necessary to stabilize such a robot and increase the rigidty of the supporting structure of each support arm. One better way of meeting this requirement is to install both servomotors for turning the first and second arms on the arm support, thus reducing the weight of the first and second arms, and to have a first arm pivot shaft supported at both ends on the arm support.
Robots of the above configuration are well known in the art. In the conventional robots however no special consideration has been given to the installation of the servomotors on the arm support. Some robots have their servomotors projecting laterally on the arm support, and hence take up a relatively large space for installation. With other robots, the range in which the first arm can swing with respect to the arm support is limited to an angle of 90.degree. between a vertical position and a horizontal position.
The multilink-type robots are generally required to provide wires and tubes such as hydraulic tubes for drive units or other accessaries on the robot. These wires and hydraulic tubes are exposed to the exterior and should be covered this arrangement makes the robot relatively large in size and restricts the ranges of motions of the parts of the robots.